Developer-Guide/datastorage/database/queries.md

Queries

Database

The database query builder provides a uniform way to write default database queries for the following databases:

• MySQL
• PostgreSQL
• SQLite
• MicrosoftSQL
• OracleSQL

Query Builder

The query builder is used for regular CRUD operations on the database.

Select, Insert, Update, Delete

Both select and insert expect the column names as parameter. The where, from and into clause can be necessary depending on the type of operation like a normal sql query.

$query->select('columnA', 'columnB')->from('table')->where(...);
$query->insert('columnA', 'columnB')->values('a', 'b')->into('table');

The update expects the table name which should be updated and then the set function to define the columns and new values.

$query->update('table')->set(['columnA' => 'a'])->set(['columnB' => 'b'])->where(...);

The delete function only expects the from and where clause to identify the to delete columns in a table.

$query->delete()->from('table')->where(...);

Random

From

The from part of a query accepts string, array, \Closure, From, Builder as parameter.

$query->select(...)->from('table');
$query->select(...)->from('tableA', 'tableB');

Into

The into part of a query accepts string, array, \Closure, Into, Builder as parameter.

Where

The basic where clause expects a column, operator, value and boolean concatenater which is used to concatenate multiple where clauses.

$query->select(...)->from(...)->where('columnA', '=', 123)->where('columnB', '=', 'abc', 'or');

For easier use additional where clauses are defined such as:

• orWhere() - same as where with or as default boolean connector
• andWhere() - same as where with and as default boolean connector
• whereIn() - uses the sql in(...)
• whereNull() - used for null condition
• whereNotNull() - used for not null condition

Limit

The limit expects an integer.

$query->select(...)->from(...)->where(...)->limit(3);

Offset

The offset expects an integer.

$query->select(...)->from(...)->where(...)->offset(3);

Order

The ordering is performed by orderBy.

$query->select(...)->from(...)->where(...)->orderBy('columnA', 'DESC');

The newest and oldest operation are a small wrapper which automatically order by DESC and ASC respectively.

Group By

Grouping of columns can be achieved through groupBy.

$query->select(...)->from(...)->where(...)->groupBy('columnA', 'columnB');

Join

Schema Builder

The schema builder is used for schema related operations such as DROP, CREATE etc.

Drop Database

A database can be dropped with dropDatabase.

$query->dropDatabase('test');

Create Table

A table can be created with createTable.

$query->createTable('user_roles')
    ->field('user_id', 'INT', null, false, true, true, 'users', 'ext1_id')
    ->field('role_id', 'VARCHAR(10)', '1', true, false, false, 'roles', 'ext2_id');

Show Tables

All tables of a database can be returned with selectTables.

$query->selectTables();

Show Table Fields

All table fields of a table can be returned with selectFields.

$query->selectFields('test');